Genetic diversity and adaptation

Question 1

-define Genetic diversity:

Answer 1

• total number of different alleles of genes in a species or population.

Question 2

WHY IS GENETIC DIVERSITY IMPORTANT?

Answer 2

-The greater the genetic diversity, the more likely that some individuals in a population will survive an environmental change.

-This is because or a wider range of alleles and therefore a wider range of characteristics.

• greater probability that some individual will possess a characteristic that is suited to the new environmental conditions.
• allows populations to adapt to their environment. If a population has a low genetic diversity, it may not be able to adapt to a change in the environment and could be wiped out by a single event e.g a disease. This would cause genetic bottlenecking.

Question 3

HOW IS GENETIC DIVERSITY INCREASED?

Answer 3

MUTATIONS - New alleles formed. Some of which will be advantageous but others could lead to problems.

MEIOSIS - crossing over and independent segregation.

RANDOM FERTILISATION - random which sperm fertilises which egg.

GENE FLOW - Different alleles being introduced into a population when individuals from another population migrate into it and reproduce.

Question 4

define genetic drift

Answer 4

-change in the frequency of an existing gene variant in a population due to random chance.

-may cause gene variants to disappear completely and thereby reduce genetic variation.